Suspension issue

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Mar 28, 2015 | 09:05 PM

Woodstoc

Thread Starter

Burning Brakes

Joined: Oct 2001

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From: Woodforest

Suspension issue

I am running one size over tires on my GS. I really like how they fill the wells, looks a lot better, and has not been an issue with handling or cornering. I now have about 38000 miles on the car, and recently I started hearing a bit of a rub in the passenger side front on agressive turns to the left.

I checked the ride height today and found the passenger side 1/2" lower than the drivers side. I had everything lowered on stock bolts and I set up the fronts the same right after I bought the car.

It took raising the passenger 1/2" to bring the front end back level. Checked and have no visible issues with the arms, bushings, spring, etc.
It's really bugging me to see the difference in the adjustments on the two sides.

Can a mono spring have one side get weaker than the other? Doesn't make sense. The only other thing I can think of is the bushing on the lowering bolts collapsing on one side. Hard to see without tearing stuff apart so that could be it. Any other ideas from the brethren?

Last edited by Woodstoc; Mar 28, 2015 at 09:08 PM. Reason: Stupid spell correct

Mar 29, 2015 | 03:42 AM

Dano523

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If the GS was corner balanced, do not touch a thing!!!!!

If not corner balanced,

Starting point is with the fender lips to the ground (with the car on level ground), and the back fender lips should be .9" higher than the front fender lips to the ground. So if the fronts are 10", the back should be 10.9" to the ground.
Note, if you have a base model, then the back end should be 1-1/2" higher than the fronts/ The fenders lips are different from a base model to a wide body.

Next, since the fenders are not always mounted square to the frame, start checking the frame points to the ground side to side, then re-adjust (don't use the .9" here), just get the fronts the same, the backs the same, then go check the fender lips again to make sure that the back fender lips are averaging .9" more than the front fender lips to the ground.

As for the factory ride height adjustment pads, then can wear over time, but on the after market units, there pads wear out very quickly instead. So if you are sporting after market adjusters, the pads on them may be cooked already.

Last edited by Dano523; Mar 29, 2015 at 03:48 AM.

Mar 29, 2015 | 10:09 AM

C U IN REARVEIW

Le Mans Master

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From: ocean springs mississippi

Also have someone else measure while you are in the drivers seat as that side will lower a bit due to added weight. Car may be level at that point. Then corner balance if desired.

Mar 29, 2015 | 10:27 AM

Woodstoc

Thread Starter

Burning Brakes

Joined: Oct 2001

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From: Woodforest

Thanks for the excellent pic comparison. I kept the stock bolts and did not cut the bushings. I'll climb back under and see if it looks like the bushings are equal, side to side. That is interesting about the fenders not being mounted the same, I never thought of that because the lines on my car were well done. I'll try frame points.

I did have the drivers side set a 1/4" higher due to my weight as an estimation, but never had someone else measure while I was in there. Good point, thanks.

My main concern was the sudden change. I had it right, then I started hearing the tire rub against the fender well on hard left turns. Something changed, have to figure out if something on the passenger side worn, or shifted.

Mar 29, 2015 | 02:13 PM

HOXXOH

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From: Peoria/Phoenix AZ

C6 of Year Finalist (performance mods) 2019

Quote:

Originally Posted by C U IN REARVEIW

Also have someone else measure while you are in the drivers seat as that side will lower a bit due to added weight. Car may be level at that point. Then corner balance if desired.

To even be more exacting, the fuel level should be halfway between full and the amount remaining at the time of a normal re-fuel.

I read many years ago that GM used a 5'9" 175# dummy in the driver's seat to create all the affected dimensions and settings. I don't know if that still exists, but with Vettes being primarily driven by older (and fatter

) men, maybe they currently do things to fit the average customer of each product.

Mar 29, 2015 | 07:10 PM

hungryhippo

Drifting

Joined: Dec 2009

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From: Benicia CA

Its most likely the stock bushing getting deformed from hard driving.

Apr 1, 2015 | 06:29 PM

Woodstoc

Thread Starter

Burning Brakes

Joined: Oct 2001

Posts: 860

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From: Woodforest

I was by informed by a dealership that the stock bushings are a "part of the spring" , not sold separately. What a crock, GM trying to hose Corvette owners for what is apparently a wear item.

Anyone know of a source for a good replacement? I do not want to lower the car due to the 295/35's I put on the car. My pads look to be hosed. I hear bad things about how the Pdfat's last.

Apr 1, 2015 | 06:58 PM

C U IN REARVEIW

Le Mans Master

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From: ocean springs mississippi

I'm running 305/30/19's on the rear heavily lowered w/o any rubbing. Have you considered going to coilovers? One of my best mods to date. Transforms the car